In his first-ever interview, the sole Australian survivor of the Waco siege has revealed to 60 Minutes what really took place during the 51-day stand-off, and why he believes crazed cult leader David Koresh will one day return to Earth as the son of God.

Bill Shorten (left) shakes hands with Malcolm Turnbull as they attend an Ecumenical Service for the commencement of the parliamentary year at the Australian Centre for Christianity and Culture in Canberra. (AAP)

And with that, the new parliamentary year was underway.

The leaders exchanged handshakes and smiles as they started the day with a visit to a church service in Canberra's south.

But it's unlikely the tone will be friendly when question time begins this afternoon.

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Parliament's citizenship crisis is expected to dominate the debate today with Coalition MPs expected to increase pressure on Mr Shorten to force Labor MP Susan Lamb to resign over a potential British citizenship.

Less than 24 hours ago, the government was threatening to use its numbers in the Lower House to refer Ms Lamb to the High Court.

But today, it appears to have softened its stance somewhat.

This morning, Mr Turnbull refused to answer questions on the issue from 9NEWS.

Turnbull speaks during an Ecumenical Service for the commencement of the new parliamentary year. (AAP)

While Education Minister Simon Birmingham said: "We're going to give Susan Lamb and Bill Shorten the chance to do the right thing.”

Finance Minister Mathias Cormann used similar language.

"We want to see what Bill Shorten does," he said.

"Bill Shorten has the opportunity to do the right thing. Bill Shorten knows Susan Lamb is in breach of the Constitution. Bill Shorten should show some leadership and he should ask Susan Lamb to resign from the parliament."

Leader of the House Christopher Pyne has stood by his earlier warning the government will take action against Ms Lamb, saying on radio the Coalition would use its lower house majority to refer her to the High Court if Labor "refused to do the right thing".

But Mr Shorten has told 9NEWS "it takes two to tango".

"There is compromise available here," he said.

He was referring to the Coalition's potential citizenship issues - with four government MPs under clouds of their own.

Labor has flagged a swap deal of sorts.

Last year, the Opposition proposed a bill that would have sent four Coalition members and four Labor members to the High Court - but the Coalition succeeded in narrowly voting it down.